Initial pre-release of the FermiLib-Plugin-Psi4 (v0.1a0)

Initial release v0.1a0

Submitted on behalf of Jarrod McClean (LBNL), Ryan Babbush (Google), Damian Steiger (ETH, Google), Ian Kivlichan (Harvard University), Thomas Häner (ETH), Vojtech Havlicek, Matthew Neeley (Google), and Wei Sun (Google)